CVE-2026-64308

Summary

In the Linux kernel, the following vulnerability has been resolved:

crypto: ccp - Do not initialize SNP for ioctl(SNP_VLEK_LOAD)

Sashiko notes:

> if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host?

The SEV firmware docs for SNP_VLEK_LOAD note:

> On SNP_SHUTDOWN, the VLEK is deleted.

That is, the initialization/shutdown wrapper here is pointless, because the firmware immediately throws away the key anyway. Instead, refuse to do anything if SNP has not been previously initialized.

This is an ABI break: before, this was a no-op and almost certainly a mistake by userspace, and now it returns -ENODEV. ABI compatibility could be maintained here by simply returning 0 in the check instead.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1c3506ea8599a3ad1b9aae5cbd573134f8d18db7 < 61cf5eef20657bff9ca235fe938a99ce5ff65c06affected
LinuxLinuxceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 92567ed9306d5a3d1b007eb4faeff30cc3ffc3e4affected
LinuxLinuxceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 8836801847b9479ac046cb18a24981e1b0b05e9daffected
LinuxLinuxceac7fb89e8da465aec3ac3c20477f912f5c3a6c < f91e9dbb5845d1e5abf1028e6df57dcf61583e1baffected
LinuxLinux6.12.75 < 6.12.96affected
LinuxLinux6.16affected
LinuxLinux0 < 6.16unaffected
LinuxLinux6.12.96 <= 6.12.*unaffected
LinuxLinux6.18.39 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References